It’s been more than two and a half years since the ship ran aground off Italy’s Giglio Island with more than 4,200 passengers aboard, killing 32 people in a disaster that drew global attention.

And it’s been 10 months since salvage teams rolled the 114,000-ton vessel off the rocks in one of the most complex shipwreck recovery efforts ever undertaken.

But there’s still more work to be done.

“We are not at the end, but we are at a critical moment,” Giglio Mayor Sergio Ortelli told reporters.

For the past 10 months, engineers have been hard at work, attaching metal boxes to either side of the ship.

After draining water from the boxes, they had to pump compressed air in its place to get the ship to float.

It was a dangerous and tricky procedure. The ship is rotting, and there’s a real risk the bottom of it could give way.

On Monday afternoon, crews will try to tug the Concordia about 30 meters to the east.

They’ll attach more chains and cables to help reinforce the bottom.

Then the full refloat begins, lifting the Concordia up, deck by deck, clearing any debris along the way.

Once the ship is completely floated, they’ll tow it — slowly and carefully — 240 kilometers (150 miles) to Genoa.

Officials say it’s likely the towing process won’t start for days, due to port restrictions. It will take five to six days for the ship to reach Genoa, officials said.

Thamm called the operation “the most daunting salvage ever attempted on a ship of its size.”

He added that the project has already exceeded 1 billion euro — and that doesn’t include the cost of the refloat, the anticipated transport to Genova or the dismantlng.

Since the wreck two years ago, 24 metric tonnes of debris, including furniture, dishes, food, personal effects and ship parts, have been recovered from the seabed.

While salvage crews continue efforts to deal with the wreckage, Francesco Schettino, the ship’s captain, is on trial on charges of manslaughter, causing a maritime disaster and abandoning ship with passengers still on board. He denies wrongdoing.

Search teams thought they had found Rebello’s remains last October. But the body divers found turned out to be Maria Grazia Trecarichi, a Sicilian had been on the cruise to celebrate her 50th birthday with her 17-year-old daughter, who survived.